Community raises concerns over leachate monitoring and groundwater impact

The Benton County government meeting on May 2, 2025, focused on the Conditional Use Permit Application for the expansion of the Coffin Butte Landfill, with significant discussions surrounding leachate management and groundwater monitoring.

During the meeting, officials addressed public concerns regarding leachate, a liquid that can seep from landfills and potentially contaminate groundwater. A key point of discussion was the number of monitoring wells in place to assess groundwater quality. Officials confirmed that there are currently 52 groundwater monitoring wells located within the soil surrounding the landfill, which are crucial for tracking any potential leachate impact on groundwater.

Additionally, it was noted that there are five leachate sumps within the lined area of the landfill, which collect leachate and pump it into a lined pond for management. However, concerns were raised about the potential risks posed by older landfill cells, specifically cells 1 and 1A, which are not lined and could allow leachate to affect groundwater.

The meeting highlighted the importance of ongoing monitoring and management practices to ensure environmental safety as the landfill seeks to expand. The discussions underscored the community's interest in maintaining transparency and accountability regarding landfill operations and their environmental impacts. Further steps will likely involve continued public engagement and detailed reporting on monitoring results as the permit application process moves forward.